1. Field of the Invention
This invention relates to interferometers and more particularly to Mach Zehnder interferometers which are one of the fundamental components in sensor systems.
2. Description of Related Art
Conventional Mach Zehnder interferometers use beam splitters and mirrors although two optical fibre directional couplers with their two arms spliced together have been used. However, the two arms are subjected to different stress distributions causing a random phase imbalance between them, thus requiring complicated techniques to balance them. More stable Mach Zehnder interferometers can be fabricated in integrated optical components but there is still a requirement for all-fibre interferometers since these are easier to interface with transmission lines.